Adding null pointer check in BaseRenderingContext2D::restoreMatrixClipStack

third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp

Index: third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
diff --git a/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp b/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
index a551d487fba442dbeeca84f3536e108717e2d085..a97029554ca2c77b4184c7fd157d94e7547cffb4 100644
--- a/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
+++ b/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
@@ -98,10 +98,11 @@ void BaseRenderingContext2D::restoreMatrixClipStack(SkCanvas* c) const {
   DCHECK(m_stateStack.begin() < m_stateStack.end());
   for (currState = m_stateStack.begin(); currState < m_stateStack.end();
        currState++) {
-    CHECK(currState->get());
     c->setMatrix(SkMatrix::I());
-    currState->get()->playbackClips(c);
-    c->setMatrix(affineTransformToSkMatrix(currState->get()->transform()));
+    if (currState->get()) {
+      currState->get()->playbackClips(c);
+      c->setMatrix(affineTransformToSkMatrix(currState->get()->transform()));
+    }
     c->save();
   }
   c->restore();